Elevator-gate latch



W. 3. SMITH.

ELEVATOR GATE LATCH.

APPLICATION FILED AuG.25. I919.

1 58,592, Patented Nov. 9, 1920.

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135 in accordance with my invention;

unirso STATES PATsNr orr cs.

winmnia s. slants, or CAMBRIDGE, MAssAcnUsnrrs.

ELEVATOR-GATE LATCH.

Specification of Letters Patent. Patented NOV; 9,1920,

Application filed August 25, i919. Serial No. 319,638

raisedgates used in connection with freight elevators.

The main. object of my invention is the provision of means forautomatically lockingthe gate alter it-has been raised and forautomatically releasing the gate when the elevator leaves the floorlanding. V r

. A further object of theinventionisthe provision of means adapted forapplication to any-form of'construction of elevator gate at low cost ofinstallation and which'requiresno cost of maintenance.

Another object of the invention is to provide means which is simple inconstruction and positive and eiiicient in operation.

Other objects of the invention will be m'orespecifically set .forth anddescribed hereinafter.

Briefly, my inventioncontemplates the provision of a latch normallyinoperative but which, by the useof aucain or other suitable means onthe elevator, is throwninto an operative position when the elevatorcomes to a stop at a hoorlandiiig and is held in that position so longas the elevator remains at the landing. The latch is so an ranged thatwhen the gate is pushed up passing by it,'the latch is thrown into aretracted position and as soon as the bottom of the gate has passedbeyond the latch it is caused by ftheforce of gravity to drop into alocking position, thereby .holding the gate so long as the elevatorremains at the floor. When the elevator leavesth'e floor the cam leavesthe latch allowing'it-to swing back into an inoperative position torelease the gate automatically, I

In the drawings illustrating the preferred embodiment of my invention,

. Figure l is a front elevation of an elevator landing. as v1ewed'fromthe elevator, showing the elevator, gateheld 111p? ralsed positioniby alatch constructed and operated to close the doorway; and

F 1g. 3 1s a front elevation of the latch on an enlarged scale, with thehousing cut away to show the latch in operative positionwith the gatelocked;

big. 4 1s a sim ar ,VlGW OlZ the latch to show the retractedposition ofthe latch as the gate is be ng pushed upwardly by. the.

latch and before it reaches the position where it is .to be locked; r

Fig. 5 is a similar view showing theposition ofthe latch when releasedby the cam on the elevator to permitthe gate to drop Fig. 6 is a sideelevation looking from left to right in Fig.- 8. i

Referring to the drawings 10 designates a housing open at the sides andhaving end extensions 12, each provided with a hole id to receive ascrew lfi whereby thehousing may be securedtoa fixed. portion of thebuilding adjacent theelevator gate when itis in a raised position..lVithin the housing is pivotally mounted on a screw-bolt 18 set in theupperpart' of the housing, a latch arm 20. Thisarm is loosely mounted onthe bolt 18 to permit it to. swing on itspivot, the upper end of the armbeing provided with two lugs 22 and 2 l which are adapted to engageastop 26 on the insideof the top of the casing and therebyito limit theswinging movement of the latch arm in bothdirections. Although it may beof any suitable shape incross-section, the latch arm is preferablyT-shaped. in cross-section in order to present a wide surface, that. isthevv head of the T, to the rear or to the right as shown. in thedrawings, for apurpose to be hereinafter explained. The lower.end of thelatch arm is curved forwardly and is bored to receive a pin. 28upon'which is mounted a latch 30, the pivoted end of thelatch beingsplit so that that end of. the latch embraces the thin forward flange ofthe latch arm. The latch arm is pivotally movable on said. pin 28 and onits lower side is provided with an, enlargement 32 which is adapted toengagethe-end of the latch arm and thereby limit the outward movement ofthe latch upon its pivot. The upper end of the latch is flat and cutatsuch an angle that it is substantially horizontal whenthe latch is inoperative position, andservesas the engaging surface for the elevatorgate. The innersideof the latch is provided with a longitudinal recess34 in order to permit the latch to be thrown up closely against thelatch arm, the thin forward flange of the latch arm lying in saidrecess.

Normally the latch swings in an tive position. The weight of the latchcauses it to drop into a forward position with relation to the latch armwith the enlargement 32 in engagement with the lower endoi' the latcharm which causes the latch arm-to swing on its pivot to a rearwardposition, that is, to the right referring to the drawings, and inthisposition the rear portionoi' the latch arm projectsfroin the housing. For throwing the latch arm forward and the latch into an operativeposition, a cam 36 is arranged onthe elevator car at such point thatwhen the car is at. thev floor landing the cam engages the back of thelatch arm and holds it in a forward position as shown in Figs. 3 and 4.V

It will be observed that the'pin 18 is arranged in the housingoli-center and that a second hole 33 is bored in the housing at the sameelevation as the pin 18 but on the" other side. This arrangement servestwo purposes. It insures the rearward projection from the'housing. ofthe latch arm 20, when in an inoperative position, so that the cam 36may engage it and throw it forward and it enables the latch arm andlatchtobe reversed in the housing by mounting thepin in the holewhich'permits the device to be secured on gate as desired. V 1

in the use of my device the latch housing l2is fastened to the'doorframe or wall l0 of the building adjacent'to the elevator gateeitherrside of the elevator 42,'and at such elevation that when the gateis ina raised position the latch30. is at a levelfjust below the bottomof the gate as i 7 shown in Fig. 1. 'Where it is; inadvisable'to mountthe housing in such a position that the latch engages the gate directly,an" angle iron 44 may be fastened to the gate by screws -4.6, said angleiron having its free end proie; ting in order to be held by the latchwhen thegate is locked. InFig. 1, l8 designates the floor orlanding, andinFig. 2, 50 designates the elevator car. The cam 36 is arranged, on theelevator car at such elevation that when the car is at a landing, thecam engages the latcharm and holds it in a forward operative position,the. cam having curved end portions so that'the'latch arm willride up onthe camwhen the latter makes or breaks engagement with it. By regulatingthe length'of the cam 36 the dropping of thegatemay be timed with relation to the movement of the car away from the floor landing. i

- The operation ofmy device is as follows: As the elevator approachesthe floor landng 48 from either direction, the gate 42 is. at the floor,closingthe entrance 'to the elevator, and just before the elevatorreaches the landing, the cam 36 comes into engagement with the latch arm20 throwing it forward into the position shown in Fig. 3 atapproximately the time that the elevator reaches the floor. The gate isthenraised by hand, a counter-balancing device gener'' ally beingprovided to facilitate the raising oi the gate. As-the gate is pushedupwardly it engages the latch 30, pushing itinwardly toward't-he latcharm-2O into the position shown in Fig. 4, provided the hous- 'ing is somounted on 1ts fixed support that the latch engages the bottom of thegate directly when in an oneratlve positlon. It

the latch is arranged as shown in Fig. 1,

not in engagement with the gate, then no eilectis noticed. until theangle iron 44 strikes the latch and pushes it inwardly as shown inFig.4, lifter the gate has passed upwardly beyond the latch the force ofgravity causes the latch tobe' thrown outwardly and forwardly into theposition shown in Fig. 3, and the gate is then allowed to drop a slightdistance and rest upon the latch. 'So long as the elevator re mains atthe floor landing, the cam holds the latch arm and latch in operativeposition as shown. in Fig.3, and the gate remains locked. V r

When the el'evatorstarts to leave thefloor landing the cam moves eitherupwardly or downwardly and finally out of engagement with the latch arm20. 'At this point the latch arm swingsrearwardly into theposition shownin Fig. 5, the weight-of the gate on the latch causing it to swingrearw'ardly until the lug 22 isin engagement with the stop 26. At-thispoint the latch'passes from underneath the 'gateallowing it to fall byforce of gravity. The counter-balancing device is generally arranged forthese gates so that the weight of the gate is not exactlycounterbalanced but isslightly greater than I the counter-balancingweight and thereby the force of gravity causes the gate to fall slowlywhen the latch is released,

It will beobserved that my latch'is extremely simple bothin constructionandoperation and can 'be made at'a low cost and after being installedrequires absolutely no ings and described hereinbefore audit-is not tobe limited to thegeneral form shown.

What I claim is 1. An elevator gate latch comprising a housing adaptedto be secured to a fixed support adjacent to the position of the gatewhen raised, a latch-arm pivotally hung at its upper end off center insaid housing, a

latch pivotally mounted on the lower end of said arm and normally heldin an outward and locking position by the force of gravity, said latchbeing movable around its pivot toward the said latch-arm in order topermit the gate to pass upwardly by the latch to its raised position anda cam carried by the elevator car for engaging said latch arm forthrowing it forward into locking position when the elevator is at thefloor landing.

. 2. An elevator gate latch comprising, a housing adapted to be securedto a fixed support adjacent to the position of the gate when raised, alatch-arm pivotally hung at its upper end off center in said housing,the upper end of said latch-arm being provided with lugs adapted toengage a stop formed on said housing in order to limit the movement ofsaid latch-arm in both directions,

said stop, a latch carried by said latch-arm for supporting the gate ina raised position when said latch-arm is thrown forward into operativeposition and a cam carried by the elevator car for throwing saidlatch-arm into operative position when said cam is at i housing andnormally inoperative, a latch pivotally mounted on the lower end of saidlatch-arm, said latch being normally held in a forward position bygravity and being provided witha stop to limit its forward movement anda cam carried by the elevator car for throwing said latch-arm into aforward operative position where said latch will lock said gate so longas said car remains at the floor landing.

In witness whereof, I hereunto set my hand this twenty-fourth day of Jul1919.

WILLIAM S. S ITH.

